Ann Marie often seemed self-absorbed, grandiose, and lacking in empathy when her personal desires were concerned. Appealing, but problematic? Or simply realistic?

I always think, "Poor Donald!"

Maybe you could supply some examples, since you say you have noticed these qualities often. Nothing comes to my mind regarding these qualities when describing Ann Marie. As humans, we all at one time or another have exhibited one or more of these traits ourselves.

Well, recently I saw one where Jerry and Ruthie were fighting/separated and Ann was really only concerned because it was wearing on her time with Donald so she manipulated everyone despite Don's refusal to get involved, broke all her confidentialities and eventually got them back together and got Donald back to herself.

Nothing unusual here for sitcom plots - harmless - it all works out in the end - and Ann Marie is really in the beloved tradition of Lucy Ricardo/Carmichael/Carter, Gidget, Patty Lane, Donna Stone (to a more subtle degree), teenage Pebbles Flintstone, Sister Bertrille, Jeannie, Samantha, and other adorable TV schemers. But would you want to date them in real life? Maybe so! : )

If you binge-watch the series, Ann does come off really whiny and bratty, especially with Donald. I suppose when it was initially aired once a week, that wasn't as apparent or jarring.

I also think they they made her character rather stupid in some episodes. I know the intention was that she was goofy and quitky, but at times it came of as really dumb.

I never saw her as bratty, but we all have our own takes. To me she was just a big ‘ol girlie girl, a little to naive for the wicked city perhaps. But I could be biased as I totally love Marlo in real life.

IMO, the real dips##t character on the show was her father. Always a bug up his a##, often over nothing. Especially the way he ragged poor Donald. And that ep where he argues with Ethel Merman; LOL in real life she would have slapped him into next Tuesday.